The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, the approaches described in this section may not be prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
The proliferation of computer technology and the growth of the Internet have greatly increased access to electronic information. One of the continuing issues is how to prevent unauthorized access to electronic documents that contain confidential or sensitive information. As a result, approaches have been developed to control access to electronic documents. For example, electronic documents are sometimes encrypted when being transmitted over public networks, such as the Internet. This makes it difficult, if not impossible, depending upon the encryption used, for an unauthorized party who intercepts an encrypted electronic document to recover the original electronic document. As another example, some organizations store electronic documents in secure locations, such as on a secure server. Access policies that indicate who has access to certain electronic documents may be used to control access to the electronic documents.
The concerns over unauthorized access to electronic documents that contain confidential or sensitive information also apply when electronic documents are being printed. Electronic documents are conventionally transmitted to printing devices in unencrypted form. Thus, an unauthorized party who can gain access to a communications link to a printing device can obtain electronic documents in unencrypted form. For example, an unauthorized party may eavesdrop on a wired communications link to gain access to electronic documents. Wireless networks are particularly vulnerable because an eavesdropper does not need physical access to a wired network and can instead eavesdrop remotely. Thus, a party can monitor wireless communications with a printing device and intercept electronic documents being transmitted to the printing device. In addition to intercepting electronic documents being transmitted to a printing device, unauthorized parties can acquire printed versions of electronic documents. For example, an unauthorized party may gain access to a printing device and removed a printed electronic document before the person who printed the electronic document. Based on the foregoing, there is a need for an approach for securely printing electronic documents that does not suffer from limitations of prior approaches.